This is the SRAM X1 1000 X-SYNC Crankset for BB30. Quality and durability combine in the SRAM X1 crankset to deliver consistent performance every time out. Featuring SRAM’s X-SYNC™ tooth profile, the X1 crankset is engineered for complete chain control. Each tooth’s thickness is CNC-machined to work seamlessly with the chain’s inner and outer links. And with five available chain rings (30-32-34-36-38), you can personalize your gear range to match the way you ride.